Method and apparatus for mechanically and electrically coupling metal terminals in a housing

Abstract: Three male terminals (20) are inserted respectively into terminal receiving chambers (2a) in a male connector housing (1) and a bus bar (31a) is inserted into the terminal receiving chambers (2a) through a through-hole (15a). As a result, the insertion side portion of the bus bar (31a) is press-fitted in reception grooves (25a) in bus bar (31a) press-fitting portions disposed beneath the through-hole (15a). Thus, the insertion side portion of the bus bar (31a) is received in the reception grooves (25a) in the three male terminals (30), and is mechanically fixed to and electrically connected to the male terminals (30), so that three insulated wires (30) connected respectively to the male terminals (20) are connected together only at the male connector housing.

Description: This invention relates to a connector terminal-joint structure for connecting a plurality of terminals together, as well as to a method for mechanically and electrically coupling metal terminals, respectively. For connecting insulated wires, juxtaposed in the same direction, there have been used previously either a branch connection (also called "joint") or a technique utilizing a branch connection box. Here, the branch connection relates to a technique in which an insulative covering is peeled from one insulated wire intermediate opposite ends thereof to thereby expose its conductor, and an insulative covering is peeled from a front end portion of the other insulated wire to thereby expose its conductor, and the two conductors are compressively clamped together by a terminal to thereby make an electrical and mechanical connection between the conductors. An example for a branch connection box has been proposed in Japanese Patent Unexamined Publication No. 61-277180. More specifically, insulated wires, each having a female terminal connected to its front end, are inserted at their front end portions into a connector housing having a plurality of terminal receiving chambers, and a plurality of male terminals, which can be inserted respectively into the female terminals disposed respectively in the above terminal receiving chambers, are provided at the branch connection box that can receive the connector housing therein. The male terminals are connected respectively to their mating female terminals. In this construction, the female terminals are connected respectively to the front ends of the insulated wires to be connected together and are inserted respectively into the terminal receiving chambers of the connector housing. Then, when the connector housing is inserted into the branch connector box, the male terminals, connected together at the branch connection box, are inserted respectively into their mating female terminals, so that the plurality of female terminals and hence the insulated wires are electrically connected together through the male terminals. Another example for a branch connecting box is disclosed in US-A-5,106,318. This known branch connecting box or branch circuit constituting structure, respectively, comprises a housing including a plurality of juxtaposed terminal chambers and through holes formed respectively through a side wall thereof and partition walls each provided between respective adjacent ones of the terminal receiving chambers, metal terminals each having a wire connection portion and an electrical contact portion which is open at opposite sides of a terminal receptive portion of the electrical contact portion and a side of said wire connection portion, and a short-circuit member insertable into the housing through the through holes. EP-A-0 387 772 shows an electrical interconnection assembly from which the present invention starts from. This known electrical interconnection assembly has a connector housing with connection openings at two sides, whereas elongated contact members fixed inside the housing project into these openings. Both end sides of these contact members constitute male terminal portions for contacting with female terminals, so that connection from both sides of the connector housing is possible. Short-circuit means in form of one or more bus-bar-plates are provided for short-circuiting two ore more contact members, either in total or in groups thereof. In the above general technique of achieving the connection by the branch connection, however, cumbersome operations such as the peeling of the insulative coverings and the compressive clamping of the terminals, have been required, and therefore it has been difficult to introduce an automated system, thus resulting in low operation efficiency. The technique utilizing the branch connection box, in addition to the connector housing, requires a separate branch connection box, and therefore extra space for mounting the box is required. When this is to be installed, for example, in an engine room or compartment of an automobile, there has been encountered a problem that the efficiency of mounting is poor. In addition, the branch connection box requires the box to be affixed to a car body or the like by tape or a bracket. This has resulted in a problem that the number of steps of the assembling operation is increased. The branch connecting box according to US-A-5,106,318 is only for electrically connecting the different terminals with each other, but there is no possibility to connect other terminals to the already short-circuited terminals, as connection space is already occupied by an short-circuit plate constituting the short-circuit member. This renders operateability and versatility of this known branch connecting box poor. The electrical interconnection assembly according to EP-A-0 387 772 suffers from the drawback that prior to insert or connect the respective terminals to be short-circuited, the individual elongated contact members must be inserted and fixed within the connector housing, thus necessitating additional operating and assembling steps. The present invention has been made in view of the above problems, and an object of the invention is to provide a joint structure and a method for connecting terminals for connector terminals in which predetermined terminals can be electrically and mechanically connected in a connector housing. Solution of this object is achieved by what is claimed in claim 1 or 4, respectively. Thus, according to one aspect of the invention, there is provided a connector terminal-joint structure for connecting metal terminals that are received in a plurality of respective terminal receiving chambers formed in a connector housing comprising: a through-hole formed in said connector housing and extending in a direction intersecting a direction of a length of said terminal receiving chambers in said connector housing, said through-hole communicating with each of said terminal receiving chambers; a reception portion at each of said metal terminals, said reception portion being registrable with said through-hole; and a short-circuiting piece in the form of a bus bar having a length equal to a length of said through-hole and being adapted to pass through said terminal receiving chambers and engage with said reception portions formed on each of said metal terminals to electrically short-circuit the metal terminals together, wherein said metal terminals each being connectable to a wire and said reception portions each being arranged in a manner that when said wire is connected to said terminal, said reception portion will be over a covering of an insulated portion of said wire. According to another aspect of the invention, there is provided a method of mechanically and electrically coupling metal terminals having reception pieces in a connector having a housing that has terminal receiving chambers and a through-hole that communicates said terminal receiving chambers, the method comprising the steps of: inserting said metal terminals into respective ones of said terminal receiving chambers; aligning said reception pieces with the through-hole; inserting a bus bar in said through-hole; and engaging said reception pieces with said bus bar. The method is furthermore characterized in that prior to inserting said metal terminals into respective ones of said terminal receiving chambers, said metal terminals each are connected to a wire; and by arranging said reception portions over a covering of an insulated portion of said wire. In the invention of the above construction, the short-circuiting piece, abutted against the reception portions of the metal terminals through the through-hole in the connector housing, electrically short-circuits the predetermined metal terminals together. Therefore, the plurality of metal terminals received in the common connector housing are electrically connected together. As described above, in the present invention, the predetermined terminals can be connected together only at the connector housing, and the single connector has a first function of an ordinary connector to connect one connector to other connector and a second function of a joint connector, and therefore enhanced versatility is obtained. Moreover, because a cumbersome operation such as a branch connection or insertion of contact members prior to attach the terminals to be short-circuited is eliminated, an automation system can be easily introduced, and the efficiency of the wire installation can be enhanced. Furthermore, a separate branch connection box or the like other than the connector housing is eliminated, and the operation for fixing such member is not necessary. Therefore, the mounting efficiency is excellent and also the number of steps of the assembling operation is reduced. This is quite advantageous particularly when the connector is to be installed at a limited mounting space as within an engine compartment or room of an automobile. By arranging the reception portions over a covering of the insulated portion of the wire, the short-circuiting piece always will be attached at a portion having a constant diameter or thickness. In other words, contrary to the portion, where the core or the insulation cover of the wire, respectively, are crimped by the respective barrel portions of the terminal, there is a fixed or given diameter and thus height at the covering of the insulated portion of the wire and thus a given degree of insertion of the short-circuiting piece is ensured without the danger of too less or too deep insertion resulting in poor contact or damage of the wires core, respectively. By pressing the short-circuiting piece onto the covering of the insulated portion of the wire by a given or predetermined degree without damaging the core of the wire, there is furthermore an additional strain-relief function for securing the wire at the terminal even upon high tensile forces. The invention will now be described in detail with reference to the following drawings, wherein: Fig. 1 is a front-elevational view showing a male connector housing and bus bar pieces; Fig. 2 is a plan view of the male connector housing; Fig. 3 is a side cross-sectional view of the male connector housing having male terminals and the bus bar pieces mounted thereon; Fig. 4 is a perspective view showing a condition in which the bus bar piece is inserted in one set of the male terminals; and Fig. 5 is a front-elevational view of an alternative form of the bus bar piece. A preferred embodiment of the present invention will now be described in detail with reference to the drawings. In Figs. 1 to 3, a male connector housing 1 includes a terminal holder portion 11, the interior of which is partitioned in such a manner that three terminal receiving chambers 2a plus two terminal receiving chambers 2b are provided at an upper portion thereof whereas seven terminal receiving chambers 2c are provided at a lower portion thereof. A hood portion 3 is provided forwardly of the terminal holder portion 11, and terminal insertion holes 12a, 12b and 12c are provided rearwardly of the terminal holder portion 11. Male terminals 20 are received in the terminal receiving chambers 2a, 2b and 2c, respectively, and a female connector housing (not shown) is inserted into the hood portion 3 of the male connector housing 1, so that female terminals are fitted on and connected to their mating male terminals 20, respectively. An elastic lock piece 13 having a lock pawl 13a is provided in each of the terminal receiving chambers 2a, 2b and 2c, the lock pawl being disposed in the terminal receiving chamber. A slit-like through-hole 15a is formed through an upper wall of the male connector housing 1 adjacent an open end of the terminal holder portion 11, and extends across the terminal receiving chambers 2a, the through-hole 15a being in communication with the terminal receiving chambers 2a. Similarly, a through-hole 15b is formed in communication with the two terminal receiving chambers 2b. A through-hole 15c is also formed through the lower wall, and is in communication with the terminal receiving chambers 2c. Bus bar pieces (short-circuiting pieces) 31a, 31b and 31c each in the form of a generally rectangular, electrically-conductive plate, are inserted into the through-holes 15a, 15b and 15c, respectively. The bus bar piece 31a connects the three male terminals 20, inserted respectively in the terminal receiving chambers 2a, together mechanically and electrically in a manner mentioned below, and similarly the bus bar piece 31b connects the two male terminals 20, inserted respectively in the terminal receiving chambers 2b, together, and the bus bar piece 31c connects the seven male terminals 20, inserted respectively in the terminal receiving chambers 2c, together. As shown in Fig. 4, a front end portion of the male terminal 20 is formed into a terminal portion 21, and a tubular barrel portion 22 of a square cross-section extends continuously from this terminal portion. An upper surface of the barrel portion 22 is open at its central portion to provide a locking notch or lock hole 22a in which the above-mentioned lock piece is engageable. A wire barrel 23 for connection to a conductor of an insulated wire 30 is formed rearwardly of the barrel portion 22, and an insulation barrel 24 for fastening a covering of the insulated wire 30 is formed rearwardly of the wire barrel 23. Further, a reception portion for receiving the bus bar piece 31a is formed rearwardly of the insulation barrel 24 of the male terminal 20. This reception portion 25 comprises opposed side portions of an inverted L-shape that allow the insulated wire 30 to pass therebetween, and a reception groove 25a is formed in each of the opposed side portions and extends downwardly from its upper end. The bus bar piece 31a can be press-fitted into these reception grooves 25a to form an interference fit. When the male terminal 20 is inserted into the male connector housing 1, the reception grooves 25a are disposed in registry with the through-hole 15a formed in the male connector housing 1. Next, the operation of this embodiment of the above construction will be described. Here, three insulated wires 30 are to be connected together. The front end of the insulated wire 30 is compressively clamped by the wire barrel 23 of the male terminal 20, and the covering of the insulated wire is compressively clamped by the insulation barrel 24. Then, each male terminal 20 is inserted into the corresponding terminal receiving chamber 2a through the terminal insertion hole 12a. As the male terminal 20 is inserted, the front end of the barrel portion 22 abuts against the lock pawl 13a of the lock piece 13 to force it upwardly, and when the male terminal is inserted into a predetermined position within the terminal receiving chamber 2a, the lock pawl 13a becomes received and engaged in the lock hole 22a, thereby primarily retaining the male terminal 20 in this position. When all of the three male terminals 20 are inserted in the same manner, the bus bar piece 31a is inserted into the terminal receiving chambers 12a through the through-hole 15a. As a result, the insertion side portion of the bus bar 31a is press-fitted in the reception grooves 25a of the reception portions 25 disposed beneath the through-hole 15a. Namely, the insertion side portion of the bus bar piece 31a is received in the reception grooves 25a of the three male terminals 20, and is mechanically fixed to and electrically connected to these male terminals 20, as shown in Fig. 4. Therefore, the insulated wires 30 connected respectively to the male terminals 20 are connected together. Upon insertion of the bus bar piece 31a, the upper edge portion of the bus bar piece 31a is engaged with the edges of the through-hole 15a, thereby secondarily retaining the male terminals 20, thus positively fixing the male terminals 20 relative to the male connector housing 1. Similarly, the two male terminals 20, inserted respectively into the terminal receiving chambers 2b, are connected together by the bus bar piece 31b, and the seven male terminals 20, inserted respectively into the terminal receiving chambers 2c, are connected together by the bus bar piece 31c. In the above embodiment, the predetermined male terminals 20 can be connected together only at the male connector housing 1, and the single connector performs the function of an ordinary connector connectable to another connector and the function of a joint connector, and therefore enhanced versatility is obtained. Moreover, since a cumbersome operation such as a branch connection is not needed, an automated system can be easily introduced and the efficiency of the wire installation can be enhanced. Furthermore, a separate branch connection box or the like other than the male connector housing 1 is not necessary, and the operation for fixing such member is not necessary, and therefore the mounting efficiency is excellent, and also the number of steps of the assembling operation is reduced. This is quite advantageous particularly when the connector is to be installed at a limited mounting space as within an engine room or compartment of an automobile. Moreover, the male terminals 20 can be retained not only primarily by the lock piece 13 but also secondarily by the bus bar pieces 31a, 31b, 31c, so that the terminal can be positively fixed. In this embodiment, although the male terminal 20 has the reception portion 25 with the reception grooves 25a, the construction is not limited to such an arrangement. For example, a flat abutment portion may be formed on that portion of the male terminal 20 abuttable with the insertion side of the bus bar piece 31a to make an electrical connection thereto, in which case the male terminals 20 are electrically connected together through abutment of the abutment portion against the bus bar piece 31a. In this embodiment, although the bus bar pieces 31a, 31b and 31 are in the form of a generally rectangular plate, they are not limited to such a shape, and for example, the bus bar pieces may have such a configuration as shown in Fig. 5. More specifically, this bus bar piece 41 comprises a strip portion 42 of a generally strip shape, and a plurality of projection portions 43a, 43b ... and 43n projected from the strip portion 42 in the same direction (toward the male terminals 20). Narrow portions 44a, 44b ... and 44n are formed respectively at connecting portions interconnecting the projection portions 43a, 44b ... and 43n and the strip portion 42. With this configuration of the bus bar piece 41, only those projection portions corresponding respectively to those male terminals 20 to be short-circuited together are kept intact while the other projection portions are broken along narrow portions 44a ... 44n and removed by a tool such as a pliers, and then the bus bar piece is inserted into the through-hole. As a result, only those male terminals corresponding respectively to the intact projection portions can be connected together, and a desired combination of the male terminals to be connected can be obtained. Thus, with this configuration of the bus bar piece 41, various connections can be achieved only by preparing a plurality of bus bar pieces 41, and this further enhances versatility. The invention has been described in detail with reference to preferred embodiments thereof, which are intended to be illustrative but not limiting. Various changes may be made without departing from the invention, which is defined in the following claims.

Claims: A connector terminal-joint structure for connecting metal terminals (20) that are received in a plurality of respective terminal receiving chambers (2a, 2b, 2c) formed in a connector housing (1) comprising: a through-hole (15a, 15b, 15c) formed in said connector housing (1) and extending in a direction intersecting a direction of a length of said terminal receiving chambers (2a, 2b, 2c) in said connector housing (1), said through-hole (15a, 15b, 15c) communicating with each of said terminal receiving chambers (2a, 2b, 2c); a reception portion (25) at each of said metal terminals (20), said reception portion (25) being registrable with said through-hole (15a, 15b, 15c); and a short-circuiting piece in the form of a bus bar (31a, 31b, 31c) having a length equal to a length of said through-hole (15a, 15b, 15c) and being adapted to pass through said terminal receiving chambers (2a, 2b, 2c) and engage with said reception portions (25) formed on each of said metal terminals (20) to electrically short-circuit the metal terminals (20) together, characterized in that said metal terminals (20) each being connectable to a wire (30) and said reception portions (25) each being arranged in a manner that when said wire (30) is connected to said terminal (20); said reception portion (25) will be over a covering of an insulated portion of said wire (30). The connector terminal-joint structure of claim 1, wherein said bus bar (31a, 31b, 31c) comprises a generally rectangular metallic strip portion (42) having a plurality of spaced projection portions (43a, 43b,...43n) that are communicable with said terminal receiving chambers (2a, 2b, 2c) and engageable with said reception portions (25). The connector terminal-joint structure of claim 2, wherein each of said projection portions (43a, 43b,...43n) is connected to said strip portion (42) with a narrowed portion (44a, 44b,...44n) such that selected ones of said projection portions (43a, 43b,...43n) are brakeable along said narrowed portion (44a, 44b,...44n) to define a predetermined pattern of metal terminals (20) to be engaged and short-circuited. A method of mechanically and electrically coupling metal terminals (20) having reception pieces (25) in a connector having a housing (1) that has terminal receiving chambers (2a, 2b, 2c) and a through-hole (15a, 15b, 15c) that communicates said terminal receiving chambers (2a, 2b, 2c), the method comprising the steps of: inserting said metal terminals (20) into respective ones of said terminal receiving chambers (2a, 2b, 2c); aligning said reception pieces (25) with the through-hole (15a, 15b, 15c); inserting a bus bar (31a, 31b, 31c) in said through-hole (15a, 15b, 15c); and engaging said reception pieces (25) with said bus bar (31a, 31b, 31c), characterized in that prior to inserting said metal terminals (20) into respective ones of said terminal receiving chambers (2a, 2b, 2c) said metal terminals (20) each are connected to a wire (30); and arranging said reception portions (25) over a covering of an insulated portion of said wire (30). The method of claim 4, further comprising providing the bus bar (31a, 31b, 31c) with a plurality of frangibly breakable projection portions (43a, 43b,...43n) and breaking selected ones of said projection portions (43a, 43b,...43n) to form a configuration that corresponds to a pre-selected configuration of said metal terminals (20) to be connected. The method of claim 4 or 5, wherein the engaging step further includes providing an interference fit between the bus bar (31a, 31b, 31c) and the reception portions (25).

Inventors: FUSE KAZUHIKO, KOSUGE SHUJI, TANAKA SEIJI, FUSE, KAZUHIKO, KOSUGE, SHUJI, TANAKA, SEIJI, FUSE, KAZUHIKO, C/O SUMITOMO WIRING SYST. LTD., KOSUGE, SHUJI, C/O SUMITOMO WIRING SYSTEMS LTD., TANAKA, SEIJI, C/O SUMITOMO WIRING SYSTEMS LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1994
Main classification: H01R31
IPC codes: H01R31